In the manufacture of relief printing plates from photocurable materials, a layer of material undergoes a curing reaction upon exposure to actinic radiation. The actinic radiation passes through a photographic negative and then through the photocurable material to selectively cure the material in a pattern corresponding to the image borne by the negative. However, there can be a loss of integrity of the image due to side effects created by actinic light reflection, refraction, and actinic light coming in at a shallow angle. Light collimation of actinic radiation is desirable to obtain high resolution or definition of printing elements or plates.